so this is a right triangle so you can use sin, cosine, or tangent. for A, you have the sides opposite and hypotenuse, which means you use sin*
sin(A) = opposite / hypotenuse
sin(A) = 56 / 75
arcsin(56/75) = A
A= about 48.3
so to the nearest degree, your answer is 48
*soh cah toa (if you dont know what that is, i can explain it)